IL18 and urolithiasis: Although we conclude no causal associations concerning the remaining 15 markers (SHBG, estradiol, total testosterone levels, PTH, CRP, IL6, IL18, IL27, IL8, IL16, IL1Ra, garlic intake, coffee consumption, alcoholic drinks per week, and smoking), these negative results are as important as the positive discoveries for a fuller picture of the complicated etiology of urolithiasis.